Start-ups operating under conditions of uncertainty and limited resources face several challenges for strategic internal communication. Meanwhile, their efforts in welcoming newcomers are of vital importance for the achievement of organisational success. This study investigates what the start-up context means for strategic organisational entry communication. Following a review of research at the intersection of HRM and entrepreneurship with implications for strategic entry communication, entrepreneurs and newcomers in six start-ups were interviewed. A thematic analysis resulted in the identification of three themes of challenges for strategic communication connected to welcoming newcomers in start-ups, namely: Aspects related to the overall organisational context and situation, aspects related to newcomers' job content and design, and finally entrepreneurs' communication skills, knowledge, and time resources. The discussion shows implications of the start-up context for strategic organisational entry communication as regards opportunities for strategic communication, as well as the content and form of the strategic entry communication. The study contributes to the body of knowledge on strategic communication in start-ups by drawing on research from the intersection of HRM and entrepreneurship, as well as generating new empirical insights highlighting challenges to strategic internal communication in start-ups, especially for the purpose of welcoming newcomers. 4 study, this paper specifically focuses on challenges for strategic communication connected to welcoming newcomers in start-ups. Following Zerfass et al.'s (2018) definition of strategic communication as encompassing "[…] all communication that is substantial for the survival and sustained success of an entity." (p. 493), HR communication during the entry process can be characterised as strategic communication, since it e.g. entails introducing newcomers to organisational values and practices, and enabling them to fulfil duties connected to their organisational roles (e.g. Taormina, 1997), ultimately enabling them to contribute to reaching organisational objectives. Within the cross-disciplinary realm of HRM research in entrepreneurial organisations, and of special interest to strategic communication within these, Welbourne and Katz (2002) note that "When any organization is born, the founder does the relationship management [...]" (p. xii). This means that entrepreneurs' communication skills, including their skills in and resources for strategic communication, are of central importance. However, additional research has pointed out that in entrepreneurial firms "The adoption of HRM practices is rarely strategic […]" (Cassell & Nadin, 2008, p. 74), and Cardon and Stevens (2004) noted that HRM in new ventures can be characterised as "muddle through practices" (p. 302). Considering the importance of human resources for start-ups and the emergence of internal strategic communication practices and products in this type of organisation (as noted by Wiesenberg et...